Difference between revisions of "Check dams"

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Check dams are small dams or weirs constructed across a drainage ditch, swale, or channel to lower the speed of concentrated flows for a certain design range of storm events and to promote infiltration.  
 
Check dams are small dams or weirs constructed across a drainage ditch, swale, or channel to lower the speed of concentrated flows for a certain design range of storm events and to promote infiltration.  
  
{{plainlist|1=
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{{plainlist|1=Check dams:
*Check dams usually consist of crushed rock gabions, or pre-treated timber up to 0.6 m in height.  
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*may be constructed of any resilient and waterproof material, including: rock gabions, earth berms, coarse aggregate or rip-rap, concrete, metal or pre-treated timber. Rocks used in check dams should have median diameter 25-75 mm.  
*Rocks used in check dams should have median diameter 25-75 mm.  
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*are used, up to 0.6 m in height; the maximum design depth of ponded water must be ≤ 0.6 m.
*The spacing of dams should not exceed the horizontal distance from the toe of the upstream dam to the same elevation on the downstream dam. See: Sizing 
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*designed for higher flow velocities should have spillways incorporated into their profile, to direct water to the centre of the swale.
*Where check dams are used, the maximum design depth of ponded water must be 0.5 m.}}
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*are usually installed between 10-20 m along the swale. The spacing of dams should not exceed the horizontal distance from the toe of the upstream dam to the same elevation on the downstream dam.  
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*should have energy dissipation and erosion control measures installed in the 1 - 2 m downstream. Examples include large aggregate or [[Turf reinforcement|turf reinforcement]]}}
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==Sizing==
 
==Sizing==
 
{{:Check dams: Sizing}}
 
{{:Check dams: Sizing}}

Revision as of 18:14, 27 September 2017

Check damsStructures constructed of a non-erosive material, such as suitably sized aggregate, wood, gabions, riprap, or concrete; used to slow runoff water. Can be employed in practices such as bioswales and enhanced grass swales. are small dams or weirs constructed across a drainage ditchA long narrow trench or furrow dug in the ground, as for irrigation, drainage, or a boundary line., swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades., or channel to lower the speed of concentrated flows for a certain design range of storm events and to promote infiltrationThe slow movement of water into or through a soil or drainage system.Penetration of water through the ground surface..

Check damsStructures constructed of a non-erosive material, such as suitably sized aggregate, wood, gabions, riprap, or concrete; used to slow runoff water. Can be employed in practices such as bioswales and enhanced grass swales.:

  • may be constructed of any resilient and waterproof material, including: rock gabions, earth berms, coarse aggregateA broad category of particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in various particulate size gradations. or rip-rap, concrete, metal or pre-treated timber. Rocks used in check damsStructures constructed of a non-erosive material, such as suitably sized aggregate, wood, gabions, riprap, or concrete; used to slow runoff water. Can be employed in practices such as bioswales and enhanced grass swales. should have median diameter 25-75 mm.
  • are used, up to 0.6 m in height; the maximum design depth of ponded water must be ≤ 0.6 m.
  • designed for higher flow velocities should have spillways incorporated into their profile, to direct water to the centre of the swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades..
  • are usually installed between 10-20 m along the swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades.. The spacing of dams should not exceed the horizontal distance from the toe of the upstream dam to the same elevation on the downstream dam.
  • should have energy dissipation and erosion controlIncludes the protection of soil from dislocation by water, wind or other agents. measures installed in the 1 - 2 m downstream. Examples include large aggregateA broad category of particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in various particulate size gradations. or turf reinforcement


Sizing

Check dams: Sizing